#include <REGX52.H>
#include "delay.h"

/**
  * @brief  矩阵键盘读取按键键码
  * @param  无
  * @retval KeyNumber 按下按键的键码值
			如果按键按下不放，程序会停留在此函数，松手的一瞬间，返回按键键码，没有按键按下时，返回0
  */
char MatrixKey()
{
 char KeyNumber='x';
	
	P1=0xFF;
	P1_3=0;
	if(P1_7==0){Delay(20);while(P1_7==0);Delay(20);KeyNumber='N';}
	if(P1_6==0){Delay(20);while(P1_6==0);Delay(20);KeyNumber='1';}
	if(P1_5==0){Delay(20);while(P1_5==0);Delay(20);KeyNumber='4';}
	if(P1_4==0){Delay(20);while(P1_4==0);Delay(20);KeyNumber='7';}
	
	P1=0xFF;
	P1_2=0;
	if(P1_7==0){Delay(20);while(P1_7==0);Delay(20);KeyNumber='0';}
	if(P1_6==0){Delay(20);while(P1_6==0);Delay(20);KeyNumber='2';}
	if(P1_5==0){Delay(20);while(P1_5==0);Delay(20);KeyNumber='5';}
	if(P1_4==0){Delay(20);while(P1_4==0);Delay(20);KeyNumber='8';}
	
	P1=0xFF;
	P1_1=0;
	if(P1_7==0){Delay(20);while(P1_7==0);Delay(20);KeyNumber='a';}
	if(P1_6==0){Delay(20);while(P1_6==0);Delay(20);KeyNumber='3';}
	if(P1_5==0){Delay(20);while(P1_5==0);Delay(20);KeyNumber='6';}
	if(P1_4==0){Delay(20);while(P1_4==0);Delay(20);KeyNumber='9';}
	
	P1=0xFF;
	P1_0=0;
	if(P1_7==0){Delay(20);while(P1_7==0);Delay(20);KeyNumber='+';}
	if(P1_6==0){Delay(20);while(P1_6==0);Delay(20);KeyNumber='-';}
	if(P1_5==0){Delay(20);while(P1_5==0);Delay(20);KeyNumber='*';}
	if(P1_4==0){Delay(20);while(P1_4==0);Delay(20);KeyNumber='/';}
	
	return KeyNumber;
}
